Pulverizing mill.



(No Model.)

Pat ented Feb. 6, I900. A. RAYMOND.

PULVERIZING MILL.

(Application filed May 6, 1898.)

4 Sheets-Sheet I,

Ja e/@501" Patented Feb. 6, I900. A. RAYMOND.

No. 642,7l7.

PULVERIZING MILL.

(Application filed May 6, 1898.)

4 Shank-Sheet 2.

(No Model.)

Patented Feb. 6, I900. A. RAYMOND.

PULVERIZING MILL.

(Application filed May 6, 1898.)

4 Sheets-Sheet 3.

(No Model.)

THE NORRIS PETERS 00.. PNoTQuTHd, wnsnmamw. n. c.

No. 642,7!7. Patented Feb. 6, I900.

A RAYMOND PULVERIZING MILL. (Application filed m a, 1898.) (No Model.) 4Sheets-Sheet 4.

wr'rnn STATES PATENT OFFICE.

' ALBERT RAYMOND, OF CHICAGO, ILLINOIS.

PULVERIZING-MILL.

SPECIFICATION forming part of Letters Patent No. 642,717, dated February6, 1900.

Application filed Mayfi, 1898. Serial No. 679,907- (No model.)

To (ZZZ whom it may concern.-

Be it known that I, ALBERT RAYMOND, a citizen of the United States,residing at Ohicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Pulverizing-Mills, ofwhich the following is a full, clear, and exact description, referencebeing had to the accompanying drawings, forming part of thisspecification.

This invention relates to improvements in pulverizing-mills especiallyadapted to the reduction ofcement and similar substances to impalpablepowder, the particular class of pulverizing-mills to which my inventionmore particularly relates being that in which the pulverizingisaccomplished by a combined crushing and grinding action of rollershaving a bodily revolution as well as an axial rotation.

The prime object of myinvention is to have the revolvingcrushing-rollers capable of free and unrestrained axial rotation andbodily movement parallel with the axis of rotation and at the same timeprovide a mill that shall be cheap and simple in construction,economical of operation, and that shall have the maximum capacity andefiiciency.

Another object is to have the grinding-faces of the rollers and bowl insuch a machine substantially parallel at all times, regardless of thedistance of the roller from the crushingring of the bowl, and henceregardless of the size of the material being operated upon.

A further object is to utilize to the maximum the gravity, as well asthe centrifugal force, of revolving rollers in the crushing andgrindingoperation, whereby is avoided the bounding and skipping of therollers in action, while the efficiency of the machine is greatlypromoted. I

Other objects are to insure the prompt discharge of the dust frombetween the grinding-rollers and the bowl without allowing the same tosettle into the bowl, to protect the bearings of the rollers against thelodgment of dust thereon, which would otherwise seriously interfere withthe operation of the machine, and to provide certain novel details forthe carrying out of these objects.

The foregoing and such other objects as may hereinafter appear areattained by the devices illustrated in the accompanying drawings, inwhich- Figure 1 represents a central vertical section through acrushing-mill embodying my invention, showing the Raymond air-separatorapplied thereto. Fig. 2 represents a central vertical section throughthe bowl of the mill. Fig. 3 represents a horizontal section through themill, taken on the line 3 3 of Fig. 1. Fig. 4 represents an enlargedvertical section on the line 4 4 of Fig. 3. Fig. 5 represents a detailside elevation more particularly illustrating the atmospheric portleading to the bearings. Fig. 6 represents a vertical section throughthe bowl on the line 6 6 of Fig. 3 looking in the direction indicated bythe arrows, but showing the rollers removed. Fig. 7 represents a detailsectional view of the crusher-head. Fig. 8 represents an oblique sectionthereof on the line 8 8 of Fig. 7 looking in the direction indicated bythe arrows. Figs. 9 and 10 represent detail perspective views of theplows.

Similar letters of reference indicate the same parts in the severalfigures of the drawings.

So far as relates to the broad idea of my invention I may here statethat it is immaterial how the impalpable powder or dust produced by mymill is removed therefrom, but for the purposes of illustration I haveshown in Fig. 1, in connection with the mill, the airseparator for whichLetters Patent of the United States No. 580,145 were granted me on the6th day of April, 1897, which apparatus is automatic in its operationwhen once the machine is set in motion.

Referring by letter to the accompanying drawings, and more particularlyto Fig. 1, the machine consists in general of a bowl A and rollers B,between which the cement is pulverized, the dust passing up through thecylindrical chamber 0 between the double cones D and E under thedeflector F and out through the discharge-pipe G, the direction of thedust being equally illustrated by the arrows, The dust is drawn out byan exhaust-fan, the induction-port of which is connected with the pipe Gand the eduction-port of which is connected with a dust-collector of anysuitable construction. From the collector the cleaned air is returned tothe spiral air-duct H surrounding the bowl of the mill, and thence intothe mill and out again inthe manner previously described, butdust-laden, thus making a complete circuit. It is not deemed necessaryto illustrate either the fan or any dust-collector, for so far asconcerns the broad idea of my invention it is immaterial how theair-laden dust is drawn out of the mill or out of the pipe G, and it isequally immatrial what becomes of the dust-laden air and whether thesame is returned after separating the dust therefrom to the mill, orwhether fresh air is continuously supplied to the mill through thesupply air-duct H, as before described.

The combination of my previouslypatented air-separator with my new millis particularly advantageous, however, because the heavy particles thatare not carried out of the separator by the air and which represent thetailings of the separator fall back directly into the mill forregrinding without any other handling, some of such heavy particlesfalling back after entering the space between the cones D and E andothers falling back after passing over and into the cone D, where theycome in contact with the aunular deflector F. This latter portion of theheavy particles must of course have means for escape from the cone D,and in my former machine flap-valves were provided in a dischargeleading to the bottom of said cone, which would openin one directiononly. In my present machine I have improved upon this arrangement byproviding a cone-valve I, adapted to enter and find a seat upon thelower end of the cone D. This valve is adjustably supported upon a rod Jand may be set at any desired point by means of a setscrew K to providea suitable opening between the valve and the cone. Obviously part of thedust-laden air, as illustrated by the arrows, must necessarily passthrough this valve-opening and of course opposes the fall of the smallerandlighter pulverized particles of cement which pass over into the coneD, but are temporarily checked by the deflector F. By a properadjustment of the valves in the opening the quantity of air pass ingthrough this channel may be readily adjusted so as to insure thecontinuous rise and discharge of the dust out through the exhaust ordischarge pipe G, while at the same time it will not be sufficientlystrong to force any of the smaller pulverized particles from the cone Dupward and into the dischargepipe.

The rod J of the ValveI may be supported in any suitable manner upon anystationary part of the machine; but because of its convenience I preferto support said rod upon the dome L of the atmospheric inlet providedfor supplying air to prevent the lodgment of dust on theroller-bearings, as will be described in detail farther on, such domeand inlet being clearly illustrated in dotted lines in Fig. 5.

The bowl A of the mill, which is stationary, is provided with a suitableannular lining M along the bottom and part way up the side walls thereofand with a wearing-ring N reaching from about the center of depth to theupper edge of the bowl, which ring constitutes the crushing and grindingface of the bowl against which the roller B works. The inner peripheryof the ring N, it will be observed, is substantially in a verticalplane, and the working face of the roller 13 is beveled, as at 0, so asto extend obliquely to the axis of the roller and substantially parallelwith the face of the ring 0. It is manifest that the working face of thering N might be at an angle instead of vertical, and the bevel orincline of the working face of the roller may be correspondingly changedso as to lie parallel therewith.

There may be any desired number of crush.- ing-rollers, four being shownin the drawings, but all of them are arranged to rotate on an obliqueaxis, and as each roller is capable of endwise movement or bodilymovement parallel with its axis the opposing grindingfaces of saidrollers and the ring N will remain always substantially parallel, nomatter how ne'ar together or far apart such faces may be and regardlessof whether these grindingfaces are in a vertical'plane or at any anglebetween the horizontal and vertical. To accomplish this, the rollers arepreferably provided with comparatively long hubs P, which are looselysleeved upon fixed stud-shafts Q,

"secured in the crusher-head B, so that when the latter is rotated therollers will be caused to revolve about the axis of rotation of the headwhich is coincident with that of the bowl and crushing-ring. The hubs ofthe rollers enter freely into recesses S in the crusherhead, whichrecesses are of sufficient depth to allow of considerable endwisemovement of the hubs upon the stud-shafts. The hubs are prevented fromleaving the studshafts and coming entirely out of the recesses by thecontact of the rollers with the ring N. In Fig. 4 the left-hand rolleris shown in its extreme outward position, while the righthand roller isshown partly retracted from the ring, as it would be when forced back bythe inner position of the material being operated upon between it andthe ring.

The crusher-head is axially supported upon a vertical shaft T, to whichthe head is keyed or otherwise rigidly secured, the lower end of saidshaft being stepped in a suitable bearing at the bottom of the machine,the bearing shown being the conical end of a threaded bolt U, projectinginto the cavity of the step and engaging the central depression in theend of the shaft. This shaft may be caused to revolve in any suitablemanner, such as by means of the beveled gear V, keyed thereon,

meshing with a corresponding beveled pinion W, mounted upon apower-shaft X, driven by a pulley Y or any other suitable manner. Itwill thus be observed that when the shaft T is rotated the crusher-headR rotates with it, and through the intermediary of the studshaft Q,entering loosely in the hubs P of the rollers, causes the latter torevolve about and within the bowl, the said rollers being forced toimpact against the crushing face or ring of the bowl under the combinedinfluence of centrifugal force and the gravity of the rollers.Consequently the maximum possible crushing force is exerted by therollers, and this of course greatly enhances the certainty of continuousand practically uninterrupted rotation of the rollers, which though freeto move away from the crushing-face of the bowl when large lumps ormasses of the material being operated upon are interposed between therollers and the bowl, yet such movement of the rollers is opposed by thecombined gravity and centrifugal force thereof, and hence there will beno slipping or uneven action thereof. In fact, such action of therollers will reduce the material being operated upon to an impalpablepowder in an unprecedented short space of time.

To insure the prompt removal of the dust or powder produced by therollers, I propose to introduce through lateral ports a in the walls ofthe bowl, at different points along the periphery thereof, jets of airwhich enter at the bottom of the bowl below the crushingring N and whichunder the influence of the suction applied to the discharge-pipe G formsa continuous upward current across the rollers and across crushing-facesthereof,carrying off the dust as rapidly as it is formed. I prefer toadmit the air to these lateral ports a from the single spiral duct H, towhich the air may be supplied to any suitable source, but obviouslythere may be separate pipes and separate sources of supply for eachport.

To prevent the lodgment of the dust upon the bearings of the rollers, Iprovide for the establishment of a current of air in the chambers S, inwhich the hubs of the rollers work, which chambers, as will be moreclearly seen in Fig. 4,-have open connection with the passage throughwhich the air is conducted. To accomplish this, I provide vertical ductsbin the crusher-head, which are open to the atmosphere through the domeL and which lead down through an annular passage formed by an apron 0,depending from the crusher-head and surrounding the hub 01 of the bowl.The course of the air in its passage through the mill is plainlyillustrated by the arrows in Fig. 4. There is no place of ingress forthe dust into the chambers S and into the hubs of the rollers except atthe ends of the bearings of the crusher-head, where protection isafforded by a packing of ordinary character. By setting up the currentpast the chamber S and down within the apron c the rising of the dust toreach this chamber is absolutely prevented, because there will at alltimes be a strong current downward through the apron induced by thesuction at the discharge end of the machine.

To prevent the accumulation of the larger and heavier particles of thematerial being worked upon in the bottom of the bowl, which might tosome extent interfere with the action of the crushing-rollers, and alsoto insure the more rapid and thorough pulverizing of the material, Ipropose to have a constant delivery of the material from the bottom ofthe bowl to the crotch formed between each roller and the bowl, whichoperation shall be continuous, notwithstanding the revolution of therollers about the bowl. To this end I provide in front of each roller aplow e, which is preferably tubular with an inclined floor and curvedlongitudinally to conform to the arc of the bowl. These plows, as moreclearly illustrated in Fig. 6, are supported upon arms f, radiating fromthe apron c, and as the apron is rigidly secured to and depends from thecrusher-head it of course rotates in unison therewith, and thus carriesthe plows along in advance of the rollers.

.plows in advance of one roller, or one or more of them, as may bepreferred, there can be no accumulation of the material in the bottom ofthe bowl, and so long as there is any material in the bowl, the rollerswill not be idle, although operating above the bottom of the bowl,because the material will be forcibly lifted up and discharged by theplows into the crushing-jaws formed by the roller and bowl. It istherefore. obvious that the effectiveness of the machine will be greatlypromoted and the product thereof greatly increased by the use of theseplows, which, though not essential to the broad idea of my invention,are at the same time desirable for the reasons above mentioned.

A pulverizing-mill embodying my invention possesses numerous advantagesoversuch machines as heretofore constructed, chief among which may bementioned the simplicity and economy of construction,the readiness withwhich worn or broken parts may be removed, the effectiveness thereof forpulverizing to almost any degree of fineness, even to the production ofan impalpable powder at a comparatively slow speed, and the utilizing tothe fullest extent the grinding and pulverizing force resulting from theoperation of the machine combining gravity with centrifugal force,whereby the successful operation of the machine may be accomplished withthe minimum expenditure for power operating the same.

It is obvious that numerous changes may IIO be made in the constructionand mode of operation of a pulverizing-mill embodying my invention, theconstruction herein illustrated being simply one form of embodiment; butall such changes are contemplated by and would fall within the purviewof my invention. For instance, while I have shown and described rollersas having a free axial rotation and bodily movement on an axis obliqueto the plane of its orbitthat is, upon studshafts extending downwardlyfrom the horizontal-obviously the degree of inclination of thestud-shafts is immaterial and will be varied according to the work to beperformed by themill.

While my invention broadly contemplates a machine in which thecrushing-rollers are capable of a free axial rotation upon fixed axes-afree bodily movement parallel with the axes thereof, but toward and awayfrom the crushing-face of the bowl while traversing their orbitsit is tobe observed as a pcculiarity of the present machine that the axes of thecrushing-rollers have a downward and outward inclination with referenceto the main vertical axes around which the rollers travel in theirorbital movement; that the downward and outward inclination of the axesof the rollers is constant or unchangeable, and that in consequence ofthis fact the crushing-faces of the rollers maintain under allconditions their parallelism with the inner surface or crushing-face ofthe ring or bowl against which they act. ther observed that owing to thedownward and outward inclination of the axes of the rollers the downwardmovement of the rollers under the influence of gravity has the efiect ofcarrying or urging the rollers outward toward the inner surface orcrushingface of the bowl. It is also to be noted that owing to theinclination of the axes the centrifugal force developed by the rapidmovement of the rollers in traversing their orbits has a furthertendency, or a tendency in addition to that of gravitation, to carry therollers outward toward the surrounding ring or bowl. In consequence ofthe facts above stated the rollers are free to rise and recede from theinner surface or crushing-face of the bowl in a manner which admits oftheir adjusting themselves easily to the varying coarseness of thematerial under treatment, while at the same time this material issubjected at all times to the crushing and grinding action betweensurfaces which are parallel and from rollers which are free to' rotateupon their axes, which are free to move toward and away from thematerial being operated upon while traversing their orbits,

and which during the operation of the machine are at all times subjectedto the combined influence of gravity and centrifugal force tending todrive them against the crushing-face of the bowl.

Having thus fully described my invention,

It is to be furwhat I claim, and desire to secure by Letters Patent, is-

1. In a pulverizing-mill, the combination with a stationary bowlprovided with a crushing-face on its inner periphery, of one or morerollers capable of a free axial rotation upon fixed axes and a freebodily movement parallel with the axes thereof, but toward and away fromthe crushing-face of the bowl and means for imparting an orbital travelto said roller or rollers, each of said rollers having a singlecrushing-face oblique to its axis of rotation and parallel with thecrushing-face of the bowl, substantially as described.

2. In a pulverizing-mill, the combination with a stationary bowlprovided witha crushing-face on its inner periphery, of one or morerollers having axes of fixed inclination and capable of a free axialrotation and a free bodily movement parallel with the axes thereof, buttoward and awayfrom the crushing-face of the bowl and means forimparting an orbital travel to said roller or rollers, each of saidrollers having a single crushing-face oblique to its axis of rotationand parallel with the crushing-face of the bowl, substantially asdescribed.

3. In a pulverizing-mill, the combination with a stationary bowlprovided with a crushing-face on its innerperiphery, of one or morerollers having fixed axes downwardly and outwardly inclined withreference to the axis of the bowl and capable of a free axial rotationand a free bodily movement parallel with the axes thereof, but towardand away from the crushing-face of the bowl and means for imparting anorbital travel to said roller or rollers about the axis of the bowl,each of said rollers having a single crushing-face oblique to its axisof rotation and parallel with the crushing-face of the bowl,substantially as described.

4. In a pulverizing-mill, the combination with a stationary bowl, of oneor more rollers having fixed axes oblique to the vertical and capable ofa free axial rotation and a free bodily movement parallel with the axesthereof, but toward and away from the crushingface of the bowl and meansfor imparting an orbital travel to said roller or rollers aboutavertical axis, substantially as described.

5. In a pulverizing-mill, the combination with a stationary bowlprovided with a crushing-face, of one or more rollers having fixed axesoblique to the vertical and capable of a free axial rotation and a freebodily movement parallel with the axes thereof, but toward and away fromthe crushing-face of the bowl and means for imparting an orbital travelto said roller or rollers about a vertical axis, said rollers eachhaving a single crushing-face oblique to its axis-of rotation andparallel with the crushing-face of the bowl, substantially as described.a

6. In apulverizing-mill, a driving-head rotating on a vertical axis,gravitating conical crushing-rollers carried by said head, their axeshaving a downward and outward inclination with reference to the axis ofthe head and an encircling ring or bowl against which said rollers act,substantially as described.

7. In a pulverizing-mill, downwardly and outwardly gravitating rollershaving axes of or bowl having a vertical or substantially vertical innersurface, in combination with conical crushingrollers arranged to travelaround the inner surface of said ring, said rollers being each mountedon an axis of fixed inclination whereby it is permitted to slide axiallydownward and outward toward the ring or bowl and vice versa withoutdestroying the parallelism between its surface and the surface of thering or bowl, substantially as described.

9. In a pulverizing-mill, the combination of the following elements: afixed ring or bowl having a vertical or substantially vertical innersurface, a central vertical driving-shaft, a head or carrier mounted onsaid shaft and a series of crushing-rollers carried by said head andarranged to travel around the interior of the ring, their axes having adownward and outward inclination and the rollers being free to gravitatein the direction of their axes, whereby they are caused to slidedownward and outward toward the interior surface of the ring under theinfluence of gravity, substantially as described.

10. In a pulverizing-mill, the combination with a stationary bowl havingan upright crushing-face, of one or more rollers loosely mounted uponthe ends of fixed downwardly and outwardly extending oblique shafts, andmeans for imparting to said rollers a free axial rotation, a free bodilymovement parallel with the axes thereof and a bodily revolution, each ofsaid rollers having a single crushing-face oblique to its axis butparallel with the crushing-face of the bowl, substantially as described.

11. In a pulverizing-mill, the combination with a stationary bowl havingan upright crushing-face, of one or more rollers loosely mounted uponthe ends of fixed downwardly and outwardly extending oblique shafts andcapable of a free axial rotation and bodily movement parallel with theaxes thereof, means for imparting an orbital travel to said roller orrollers, said rollers having oblique crushing-faces parallel with thecrushing-face of the bowl, and means for admitting air to the bowl at apoint below the contacting surfaces of the roller and bowl,substantially as described.

12. In a pulverizing-mill, the combination with a stationary bowl havingan upright crushing-face and an exhaust-chamber above the bowl, of oneor more rollers loosely mounted upon downwardly and outwardly extendingoblique stud-shafts and capable of a free axial rotation and a freebodily movement parallel with the axes thereof, said rollers havingoblique crushing-faces parallel with the crushing-faces of the bowl,means for imparting an orbital travel to said roller or rollers andmeans for admitting air to the bowl at a point below the contactingsurfaces of the roller and bowl, substantially as described.

13. In apulverizing-mill, the combination with a stationary bowl, anupright shaft extending axially through said bowl,the crusher headsecured to said shaft, and one or more fixed stud-shafts projectingdownwardly and outwardly from said head, of a roller loosely mounted oneach of said shafts and capable of free bodily movement parallel withthe axes thereof, and means for rotating the upright shaft,substantially as described.

14. In a pulverizing-mill, the combination with a stationary bowl havingan upright crushing-face, an upright shaft extending axially throughsaid bowl,a crusher-head rigidly secured to said shaft, and one or morefixed stud-shafts extending downwardly and outwardly from said head, ofa roller loosely mounted on each of said shafts and'capable of a freebodily movement parallel with the axes thereof, each of said rollershaving 01)- lique crushing-faces parallel with the crushing-face of thebowl, substantially as described.

15. In a pulverizing-mill, the combination with a stationary bowl, anupright shaft extending axially through said bowl, a crusherhead rigidlysecured to said shaft, and studshafts extending obliquely from saidhead, of a roller loosely journaled upon each of said shafts and capableof bodily movement parallel with the axes thereof, an apron depend-.

ing from said head and opening into the bottom of the bowl, means forexhausting air from the bowl, means for admitting air to the bowl belowthe contacting surfaces of the rollers and bowl, ducts extending throughthe crusher-head and opening within said apron, the bearings of therollers being open to said ducts and said ducts being open to theatmosphere, and means for rotating the upright shaft, substantially asdescribed.

16. In a pulverizing-mill, the combination with a stationary bowl,crushing-rollers and means for imparting to said rollers an orbitaltravel about the bowl, of a series of tangentiallyarranged air-ductsopening into the bowl below the crushing-face thereof, substantially asdescribed.

17. In a pulverizing-mill, the combination with a stationary bowl havingan upright crushing face, an upright shaft extending meeting said ductwith the interior of the bowl axially through said bowl, a crusher-headrigin a plane below the crushing-face thereof, IO idly secured to saidshaft and one or more substantially as described.

conical rollers carried by said crusher-head, H

each of said rollers having oblique crushing- ALBER l RAYMOND facesparallel with the crushing-face of the .Vitnesses:

bowl,of a spiral air-duct surrounding the bowl F. H. DRURY,

and a series of tangential air-passages con- 1 (J. L. 700D.

